DragonFly On-Line Manual Pages

al_get_opengl_proc_address(3)                    al_get_opengl_proc_address(3)

NAME
       al_get_opengl_proc_address - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro_opengl.h>

              void *al_get_opengl_proc_address(const char *name)

DESCRIPTION
       Helper to get the address of an OpenGL symbol

       Example:

       How to get the function glMultiTexCoord3fARB that comes with ARB's
       Multitexture extension:

              // define the type of the function
                 ALLEGRO_DEFINE_PROC_TYPE(void, MULTI_TEX_FUNC,
                    (GLenum, GLfloat, GLfloat, GLfloat));
              // declare the function pointer
                 MULTI_TEX_FUNC glMultiTexCoord3fARB;
              // get the address of the function
                 glMultiTexCoord3fARB = (MULTI_TEX_FUNC) al_get_opengl_proc_address(
                    "glMultiTexCoord3fARB");

       If glMultiTexCoord3fARB is not NULL then it can be used as if it has
       been defined in the OpenGL core library.

              Note: Under Windows, OpenGL functions may need a special calling
              convention, so it's best to always use the
              ALLEGRO_DEFINE_PROC_TYPE macro when declaring function pointer
              types for OpenGL functions.

       Parameters:

       name - The name of the symbol you want to link to.

RETURN VALUE
       A pointer to the symbol if available or NULL otherwise.

Allegro reference manual                         al_get_opengl_proc_address(3)